In the conventional yarn spinning frame, the spinning rings are supported in a stationary position on a ring rail and a traveller rotates on the ring. For some years it has been recognized that there are advantages to rotating the normally stationary spinning ring and various types of support assemblies have been proposed for supporting the spinning ring for rotation and imparting a driving movement thereto. These prior types of support assemblies have included a metal support for the spinning ring, and a ball bearing between the ring support and a metal mounting bracket fixed on the ring rail. This type of metal ring supporting assembly is very expensive because the metal ring support and mounting bracket must be machined to very close tolerances. To be effective, these parts must rotate at a relatively high speed and the metal parts can be heated a sufficient amount to cause a variation in the dimensions of the metal parts and create an interference fit of the ball bearing. An interference fit can occur when the inner ring of the ball bearing is mounted on a metal ring support which will expand when heated, and the outer ring of the ball bearing is mounted in a metal mounting bracket which will expand when heated. Under these conditions, inwardly directed pressure is applied against both the inner and outer races of the ball bearing so that there is less internal clearance for the ball bearings and the ball bearing wears at a faster than normal rate. An example of this type of metal ring support assembly and one type of drive therefor is illustrated in the Costales et al U.S. Pat. No. 4,112,666.
Additionally, this metal ring support assembly is extremely heavy and the ball bearing can become clogged with lint. If the metal ring support is not completely round and balanced, extreme vibrations will be set up in the ring rail and the spinning frame.